Breath-controlled anesthetic applicator and method of operation



Dec. 5, 1967 s. w. NELSON 3,356,088

BREATH-CONTROLLED ANESTHETIC APPLICATOR AND METHOD OF OPERATION FiledSept. 25. 1963 2 Sheets-Sheet 1 so I 25 59 2O 6. g I N 46 47 43 45 9o-.1

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I N VEN TOR.

United States Patent 3,356,088 BREATH-CONTROLLED ANESTHETIC APPLICA- TORAND METHOD OF OPERATION Sidney W. Nelson, Columbus, Ohio, assignor toThe Board of Trustees of the Ohio State University, Columbus, Ohio, aninstitution of Ohio Filed Sept. 25, 1963, Ser. No. 311,461 14 Claims.(Cl. 128-488) This invention relates generally to a method and means ofadministering medication, and particularly to apparatus for applyingmedication or anesthesia directly to the internal area of interest in acontrolled and accurate manner and without danger or discomfort to therecipient.

In recent years medical advances have been made in the examination andtreatment in illnesses affecting the pharynx, bronchial tree and otherparts of the body reached through the mouth opening. Unfortunately,however, these advances have often not been utilized, and in manyinstances the examination and treatment of these internal illnesses havebeen purposely avoided or neglected. Adequate topical anesthesia isvital to the success of bronchography or endoscopy of the larynx andtracheobronchial tree, and, unfortunately, the conventional methods oftopical anesthesia of the respiratory tract that are being used causeapprehension, gagging and coughing which create an ordeal for both thephysician and the patient.

There have become commercially available, in recent years, manualaerosol methods and sprays, and even more recently, a spray-type ofanesthetic. Some alleviation of the problems in application of topicalanesthesia of the respiratory tract has attended the use of manualaerosol methods. Again, however, manual aerosol methods have not beenvery satisfactory in the general application of topical anesthesia fromeither the patient or anesthetist standpoint. This type of anesthesiarequires considerable cooperation from the patient, and in manyinstances, such as in elderly patients, and especially so in thoseexperiencing hardening of the arteries of the brain, cooperation islacking. Also, from the standpoint of the anesthetist, there is no wayto determine the amount of anesthesia administered to the patientandwhether the anesthesia that has been administered to the patient hasreached the critical area to be examined. Consequently, even anexceptionally well trained anesthetist would not be able to administerthe commercially available spraytype anesthesia in a controlled andaccurate manner. A positive pressure method also has been devised toadminister an aerosolized anesthetic agent employing the Bennett-type ofvalve. But, again, this method delivers much of the anesthetic agent tothe alveoli where it is not needed (no nerve endings) and where unwantedabsorption into the blood stream can occur.

The present invention is an improved method and means of applyinganesthesia to the patient utilizing an aerosolized anesthetic agentwhich is highly effective, accurately controlled, and without discomfortto the patient. Essentially, the basis for the present invention is anautomatic method of administering an aerosolized anesthetic agent to thepatient during normal inspiration by means of breath-actuated valves. Ingeneral, the apparatus consists of an inhale-exhale closed-loopmechanical valve system that is actuated in its initial cycle by theinhalation of the patient and then reset by the exhalation of thepatient. In this way there is administered to the patient duringinhalation a controlled amount of aerosolized anesthesia. Morespecifically, the system comprises in a preferred embodiment anaerosolized anesthetic agent opening into a breathing tube to be fittedinto the mouth of the patient and associated mechanical and electricalapparatus for activating the anesthetic spray upon each inhalation andresetting the system upon exhalation.

It is accordingly a principal object of the present invention to providea new and improved method and means of applying medications to apatient.

It is ,a further object of the present invention to provide a new andimproved method and means of applying medications to a patient that maybe accurately controlled in an effective manner and without discomfortto the patient.

Another object of the present invention is to provide an improved methodand means of applying topical anesthesia to the respiratory tract of thepatient utilizing a physiological method of delivering an aerosolizedanesthetic agent.

Another object of the present invention is to provide an improved methodand means of applying medications 1 to a patient utilizing a system andapparatus activated by the breathing of the patient.

Another object of the present invention is to provide an improved methodand means of applying medications to a patient that may be adapted toand become a part of accepted medical practice thereby permitting themedical profession to fully utilize the medical advances in thetreatment and examination of illnesses and diseases to bronchography orendoscopy of the larynx and tracheobronchial tree and to other parts ofthe respiratory tract reached through the mouth opening.

Still another object of the present invention is to provide an improvedmedical system and apparatus that is rugged, reliable and continuouslyoperable without fault, but yet is relatively simple in construction topermit manufacturing reproduction with consistency.

Other objects and features of the present invention will become apparentfrom the following detailed description when taken in conjunction withthe drawings in which:

FIGURE 1 is a pictorial schematic of a complete preferred embodiment ofthe invention;

FIGURES 2, 2a, and Zb-illustrate the operation of the breathing tube ina complete cycle of operation;

FIGURES 3 and 3a illustrate in detail the two-state operation of themetering valve in the anesthesia spray; and,

FIGURE 4 is a graph illustrating the particle size vs. weight of theanesthetic Xylocaine.

Although an aerosol anesthesia system has been known,

the implementation of the system to a practical uncomplicated method ofcreating a small aerosol cloud during the inhalation phase ofrespiration has been difiicult.

Various methods of actuating aerosols with cylinders of compressed gasas the aerosolizing force, etc., were studied, but their bulk andcomplexity eliminated their use in a practical system.

It was the next expedient, therefore, that a metering valve be used witha liquid carrying agent as both the propellant and solvent for theanesthetic since various types of metering valves were already beingused for the manual administration of aerosolized medications fromoperation of the invention, is the proper choice of anesthesia and theaerosolized agent.

In accordance with its general concepts, the system of the presentinvention, as shown in FIGURE 1, comprises a mouth piece 10, a fluttervalve 15, a diaphragm actuated switch 20, a power source 30, a counter35, an electrical solenoid 49, an anesthesia vial 50, and a meteringvalve 60.

The system is a closed loop system, i.e., the electrical/mechanicalarrangement of components are each operative in sequence and one inresponse to another from the initiation to the completion of theoperation.

The mouthpiece or breathing tube is of an appropriate size toconveniently permit its end 10a to enter to the mouth opening of thepatient. The breathing tube should, of course, be made of material suchas stainless steel that may be readily sterilized. Inserted through afirst cross-sectional aperture in the breathing tube 10 is the aerosolshaft 51.

Next positioned on the breathing tube 10 is the air pressure line 25opening at one end into the tube 10 and at its other end into thediaphragm switch valve 20. Adjacent the air pressure line 25 is the airvent or sleeve valve structure 22 fitted in an air ti-ght manner througha second cross-sectional aperture in the breathing tube 10. The sleeveof the air vent 22 is open at its upper end 27 into the atmosphere andalso has ports therein to permit outside air to enter the tube 10.

At the extreme other end of the breathing tube 10 is the two-positionflutter valve 15. In the preferred embodiment, the flutter valvegenerally comprises a plug-like insert 14 having means to allow thecomplete exhaust of air on exhalation and to permit the passage of asmall amount of outside air into the end 1% of tube 10. A rubberdisc-like member is movably positioned on the end of the valve 15.

As mentioned above, the other end of the air pressure line is connectedto the diaphragm switch 20. This element is commercially available andagain, per se, does not form a part of the invention. In a typicalillustration, it would include a pressure cylinder having, internally, abutterfly-type of diaphragm structure. The diaphragm is so positioned inthe pressure cylinder that it is permitted normally to be in a freeposition but movable with a change of pressure in the outer cylinder.Also within this element is an open electrical circuit includingcontacts adapted to become closed by the butterfly-type diaphragm whenit is moved.

The electrical circuit 30, in this particular embodiment, comprises analternating current source and a selenium rectifier for converting thepower to direct current. It is, of course, apparent a DC. power pack maybe substituted for the electrical source shown. A counter is connectedto the electrical circuit 30 to count the number of times the circuit isactuated. This counter further includes a shut-off switch for concludingthe operation of the system when a predetermined amount of actuationshave occurred.

Connected to the electrical source is a DC. solenoid secured to thehousing 90 by bracket 48 and adjustable in position by adjustable screw49. In a conventional manner, the completion of the electrical circuitrycauses magnetization of the arm 42 and hence draws (attracts) the arm 42within the core. At the outer end of the arm 42 is a first pivotal joint41 connected to one end 44a of the L shaped linkage 44. To maintainpositioning of the linkage 44 within the housing 90 and relative to theother elements therein, the elbow 46' of linkage 4.4 is pivotallymounted by mounting 47 to the outer housing 90. Centrally positioned onthe other half 44b of the L shaped linkage is a second pivotal joint 43.Also connected to this joint is a spring loaded shaft 61. A thirdpivotal joint at the second end of the linkage 44 is connected to a rod'24 that forms a part of the air vent 22. Through the connection of thepivotal joint 46 of the linkage 44 to the inner wall of the outerhousing 90, the upper arm 44b of the L shaped member is caused to moveupwardly as its lower arm 44a is moved inwardly by the withdrawal of thesolenoid arm 42.

The spring loaded shaft 61 is so positioned between support 59 connectedto the housing and the pivotal joint 43 to the linkage arm 44b, thespring action will cause the L shaped arm 44b to return to its normalposition when the electrical circuitry is broken, i.e., when thesolenoid is demagnetized. This, in turn, also causes the end joint 45,connected to the air vent shaft, to force the rod 24 downwardly andhence to return to its normal position; and, as set forth hereinafter,close the air vent to the breathing tube 10. Resting on the springwithin the shaft 61 is the rod 58 having the seat 57 at its other endfor seating the vial 50. Through continuous linkage of the solenoid 40,linkage 44, shaft 61, and the seat 57, the vial 50 is raised upwardlywhen the electrical circuit is closed. The vial 50, in turn, by upwardmovement, activates the metering valve 60, thereby introducing a passagetherein to permit the aerosolized anesthetic agent to pass from its highpressure position into a low pressure area in the breathing tube 10.

Also through continuous linkage of rod 24 with respect to the linkagearm 44a, the air vent 22 is permitted to form an air opening when it ismoved up into the breathing tube 10 and to close the same when it isreturned to its normal position.

Referring now specifically to FIGURES 2, 2a, and 2b, there isillustrated in detail the three cycles of operation of the breathingtube 10. The condition shown in FIGURE 2 is the initial or quiescentcondition. The anesthesia vial 50 is retracted and pressure sealed, theair intake tube 22 is also retracted, preventing air to be taken in, andthe flutter disc 18 is in its outwardly position permitting a free flowof air to pass through the openings 19.

When the patient breathes in, the flutter disc 18 of valve 15immediately closes the ports 19 by occupying its closed position asshown in FIGURE 2a. By preventing air to be taken in, the air is pulledfrom the tube 25 and consequently there is a decrease in the pressure onthe pressure switch 20, as set forth above. This causes air vent tube 21to be raised in its sleeve 22, thereby permitting its aperture 26 in thesleeve 22 to become registered with the aperture 28 in the inner airvent. This, in turn, permits air to be sucked in by the patient throughthe outside opening 27. The sleeve 22 may be supported at its lower endbeneath the major housing 90 by the flange 22a integrally formedtherewith. Simultaneously, with the air intake, the vial 50 is pushedupward permitting the spray nozzle 55 in the shaft 51 to become a lowpressure area for the aerosolized anesthetic fluid and thereby expelledthrough port 53. An anesthesia spray is thereby expelled into themouthpiece 10, and together with the air from the air intake 27, istaken by the patient.

To secure the shaft 51 in the tube 10, it is fixedly positioned by thethreaded nut 52 at its uppermost end and by the washer type positioner54 at its other end. The washer 54 further serves to maintain thebreathing tube 10 in its proper position relative to the housing 90. Theshaft 51 has drilled therein an aperture 55 registering at one end withthe port 53 and at its other end with the opening 76a of the anesthesiavial 50.

When the patient exhales, the air pressure in diaphragm valve 20 becomesgreater and consequently opens the switch, as also set forth above. Thiscauses the anesthesia bottle to become retracted as shown in FIG- URE 2band the air vent tube 22 to be dropped. The ports 26 and 28 aredisaligned cutting off the opening to the outside air. The anesthesiaand the air intake are thusly cut off. The flutter valve 18 is shown inFIGURE 2b in its closed position merely to illustrate that its movementis last to be affected by the patient exhaling. However, since all otheropenings in the tube 10 are closed,

the air exhaust from the patient exhaling passes around the sleeve 22and causes the flutter valve 18 to move outwardly and thereby releasesto the atmosphere the patients breath through the openings 19.

The construction of the flutter valve 15 comprises in a preferredembodiment a disc-like plug insert 14 that is fitted in the end 10b ofthe mouthpiece 10 and thereby sealing the opening 1%. A series of ports19 are conveniently placed in the insert 14. Centrally fixed to theinsert 14 is a T-type structure comprising a neck 12 and an end plate17. Of substantially the same size as the end plate is a rubber-likedisc 18 that is slideably fitted on the neck 12 and operative to sealoff the ports 19. The screw 16 is an adjustment to control the length oftravel of the diaphragm 18 and thereby control the air entering orexhausted from the ports 19.

In operation of the metering valve 60, reference is made to FIGURES 3and 3a. When the anesthetic bottle is in its normal position, themetering valve 60 is positioned as that shown in FIGURE 3. The plungervalve 70 is retracted, permitting an opening around the guide stem 74 inthe seal 72, thereby allowing the aerosolized anesthetic agent to enterthe metering area 66. At the other end of the valve 60 the seal 62 hasabutted thereto the upper cap 78 of the stem 80 to prevent the escape ofthe pressurized fluid entering the metering area. When the meteringvalve is activated, as set forth hereinabove, the plunger valve 70 joinsthe opening in the seal 72 preventing further entry of anesthesia intothe metering area 66. At the other end, however, the cap 78 and theupper tube 64 are retracted within the metering area. The opening 76aprovides a low pressure area for the pressurized fluid in the meteringarea 66 carrying the aerosolized anesthetic agent into the aperture 55of shaft 51 and hence out of port 53 (FIGURE 2) into the breathing tube10.

Upon deactivation of the metering valve, the spring 68 yieldingly ungesthe stem 80' and hence cap 78 to return to its normal upward position,wherein again the expulsion opening 76 is sealed and the metering areais again opened to the anesthesia.

The apparatus defined above cooperatively forms a closed-loop controlsystem for anesthetizin-g a specific body area of a patient. Thesequence of operation of the preferred embodiment in a typicalapplication may now be described.

In the normal inactivated condition of the system adjoining themouthpiece or breathing tube 10, the patient will simply inhale andexhale air through in the two-psition flutter valve 15. The valve 15, atthis time, will permit air to be taken into the tube as well as'toexhaust the tube 10. In the active condition of the system-foradministering the anesthesia to the patient as the patient inhales, airis pulled into the mouthpiece or tube 10 through the opposite end 1012and the flutter valve 15. A fraction of a second later, duringinhalation, the flutter valve closes, resulting in a sudden drop inpressure that is applied to the diaphragm 20 via pressure tube 25. Thedecrease in pressure, in turn, causes the diaphragm in the switch 20 tochange position and make electrical circuit 30. The electrical circuitonce completed, applies an electromotive force to the solenoidmagnetizing the arm 42 and drawing it inwardly towards the core. As thearm 42. of the solenoid is moved inwardly, the lower segment of thelinkage arm 44 is moved inwardly and through the elbow connection 46,the upper segment 44b of the linkage arm 44 is moved upward. The uppersegment 44a of the linkage arm 44 as it moves upward pushes the springloaded shaft 61 upwardly and consequently the anesthesia vial is movedupwardly. In this way the metering valve for the anesthesia having itscasing integrally formed with the vial 50 also is moved upwardly. This,in effect, lowersits needle val-ve into the vial 50. The metering valvebeing actuated causes a given amount of anesthesia to enter a smallspray tube 6 in the mouthpiece and to be aerosolized through the orifice53 into the breathing tube 10.

Simultaneously, with the activation of the metering valve 60, the airvent shaft 24 being connected to linkage arm 44b is also moved upwardly,permitting the ports 26 and 28 to register, therefore opening a directpassage 27 to permit air to enter the breathing tube 10. Thusly, thereis permitted an uninterrupted free flow of room air to carry thesimultaneously aerosolized anesthetic agent into the tracheobronchialtree during the remainder of the inhalation.

In the return cycle, i.e., during the expiratory phase of respiration,the breath actuated flutter valve 15 on the end 10b of the breathingchamber 10 opens permitting the exhaled air to escape through ports 19.Again, this builds up a pressure in the chamber 20 which causes thediaphragm to return to its original position and consequently breakelectrical contact. With the current cut off, the solenoid 40 willbecome demagnetized and consequently permit arm 42 to be returned to itsoutward position and linkage arm 44 to its original position with thehelp of the force supply by the spring in the shaft 61. This actioncauses the vial 50 to be lowered to its resting position, and in thisway resets the metering valve. The linkage arm 44 also lowers the rod 24which shuts off the air intake and the system is again ready for thenext cycle. In actual practice, little force is required by the systemand through continuous breathing the system is substantially acontinuous cycle of operation.

The vial 50 carrying the aerosolized anesthetic agent in the preferredembodiment comprised a 50 cc. glass vial containing a 10% solution ofXylocaine. This anesthetic is prepared by suspending crystallineXylocaine in a mixture of Freon 12 (20%) and Freon 114 which remains aliquid at three atmospheres of pressure. During the unactuated state(i.e., during exhalation), the three atmospheres of pressure within thevial 50 forces the Xylocaine-Freon solution through a small plastic tube63 leading from the bottom of the vial into the metering chamber. Afterthe actuation, the liquid Freon at three atmospheres of pressure quicklyflows from the metering chamber into the spray tube, from which it isaerosolized through a tiny orifice 53 into the mouthpiece 10 wherenormal atmospheric pressure rapidly causes the liquid Freon to become agas. Thus, the Xylocaine crystals remain in the form of a solid particleheterogeneous aerosol which is inhaled physiologically into the pharynxand respiratory tract.

At the present time the volume of the metering chamber (60 cu. ml.) andconcentration (10%) of the Xylocaine results in the aerolization of sixmilligrams of crystalline Xylocaine during each activation; i.e., duringeach inhalation. This knowledge allows precise control of the amount ofanesthetic agent administered so as to avoid exceeding known safemaximal amounts.

The retention of airborne particulates within the respiratory tract hasbeen theoretically calculated. The amount of an airborne particulatewhich is deposited in the respiratory tract and the location in which itis deposited are functions of particle size. The deposition of aerosolparticles in various portions of the respiratory tract has also beenexplained.

A heterogeneous aerosol such as the anesthetic Xylocaine contains a widespectrum of particle sizes (see FIG- URE 4). The theoretical andexperimental data indicates that the vast majority of particles largerthan 30 micra in diameter are deposited in the bronchial tree, whereasthe majority of particles in the 310 micra diameter range are depositedin the bronchioles and alveolar ducts. Many particles l-3 micra indiameter reach the alveoli and are probably deposited there. Particlesless than 0.5 micra in diameter easily reach the alveoli, but probablymany of these particles are exhaled again without being deposited. Thus,the theoretical particle size distribution curve of the anesthetic usedby us shows that approximately 30% of the Xylocaine is 30 micra orgreater in diameter, these being previously deposited in the mouth,pharynx, larynx, and trachea. Approximately 50% of the Xylocaine is inthe form of particles 10-30 micra in diameter, thus affording thedeposition of an adequate amount of anesthetic in the bronchial tree.Approximately 25% of the Xylocaine is in the form of particles 3-10micra in diameter, thus providing anesthesia to the level of thealveolar ducts. Only about 6% of the Xylocaine is in the form ofparticles 3 micra or less in diameter, thus fortunately precluding thepassage of a significant amount of anesthetic agent into the alveoliwhere anesthesia is unnecessary because of the absence of sensory nerveelements, and where rapid absorption of the Xylocaine mighttheoretically create a hazard.

The first two or three inhalations of the agent taste somewhat bitter,but the patient is told to expect this. As a result of the briefpreliminary instructions from the radiological technician, the patientactually anesthetizes himself in three or four minutes. Shortly afterthe procedure begins, the patient feels numb in the mouth, pharynx,larynx, and substernal region.

The technician can easily administer the aerosol anesthesia, althoughthe physician should be available at all times to treat the occasionalreaction to the anesthetic agent. The patient is instructed to inhaleand exhale with a little more than usual vigor, and is encouraged tobreathe deeply and slowly to permit the maximal amount of crystallineXylocaine to be deposited upon the mucosa.

Quantitative studies now under way indicate that of the anesthetic agentis deposited in crystalline form on the inner wall of the breathing tubeduring inhalation. An additional small amount may be lost through theflutter valve during exhalation, but this amount is not known.Theoretically, then, the maximum amount of anesthesia that can reach thepatients mouth, pharynx, larynx, and tracheobronchial tree is 75-80% ofthe anesthesia released by the metering valve. It is believed by manythat it is safe to give 200-300 mgs. of Xylocaine intratracheally. TheLD 50 (lethal dose in dogs, i.e., toxicity wherein 50% of dogs will notsurvive) in animals and the therapeutic ratio are much greater forXylocaine than for Pontocaine and Cocaine. With the method heredescribed, 40 inhalations result in the release of 240 mgs. ofXylocaine, of which about 170-180 mgs. actually enter the patients oraland respiratory structures. The supplemental use of 10 ccs. of aqueous1% Xylocaine through the endotr-acheal catheter adds 80-90 mgs., thetotal amount being about 250-270 mgs. of Xylocaine for most patients. Asmuch as 55 activations (330 mgs. of Xylocaine) have been used for largepatients or those having excessive secretions. In small women andchildren 20-30 activations are sufiicient.

Although the clinical results have been exceptionally good with the useof Xylocaine as an anesthesia as described above, it is to beunderstood, of course, that the invention is not to be so limited andother known anesthesias may be substituted therefore. Similarly, theagent Freon is merely illustrated as being particularly adaptable to theanesthesia used. Again, however, other agents for carrying theanesthesia or medication may just as readily be utilized.

An automatic counter can be preset to determine the number ofactivations for a given patient, the counter automatically concludingthe operation of the system by electrical interruption when thepredetermined number of actuations (inhalations) have been completed. Asmall red signal light may be connected to the counter and placed on thetop cover of the unit to signal the completion of the procedure.

By using the aforementioned method and equipment, more than ninetypercent of almost three hundred patients have obtained satisfactoryanesthesia with very little time and effort expended by the physicianand with reasonably little discomfort to the patient. Good anesthesia isan absolute prerequisite for precision spot-film bronchography, which,in turn, is essential for the most detailed study of the wide variety ofbronchopulrnonary diseases which can be clarified by this diagnosticapproach. It is hoped that this method of applying topical anesthesia tothe tracheobronchial tree will result in the increasing utilization ofbronchography by radiologists.

Naturally, this method of anesthesia is applicable to endoscopicprocedures of the larynx and tracheobronchial tree. Furthermore, it isproving useful in performing positive contrast examinations of thehypopharynx and larynx. It should also be very useful for direct digitaland bimanual examinations of lesions of the mouth, pharynx, and larynxwhen precise evaluation of extent of a cancerous lesion is beingattempted prior to therapy.

This automatic method of aerosolizing anesthesia, as described above, isnot to be so limited and may be applicable to other problems in clinicaltherapy. The word medication, as used herein, is intended to includeanesthesia since the system will readily adapt itself and be operable inthe same method and manner in applying other forms of medications to thepatient in the treatment of internal illnesses.

What is claimed is:

1. A closed loop system for incrementally administering a predeterminedamount of medications to a patient comprising; a patients breathingmeans having a first opening adapted to be received by the patient, anoppositely positioned second opening including a two-position elementcyclically closing said opening upon inhalation and providing an airoutlet upon exhalation, means containing an aerosolized medicated agenthaving a dispensing means also opening into said breathing means, andmeans connected to said breathing means and operative with saidtwo-position element for cyclically activating said dispensing meansupon inhalation and for deactivating said dispensing means uponexhalation of the patient.

2. A closed loop system for incrementally administering a predeterminedamount of medications to a patient comprising; a patients breathingmeans having a first opening adapted to be received by the patient, anoppositely positioned second opening including a two-position elementcyclically closing said opening upon inhalation and providing an airoutlet upon exhalation, means containing an aerosolized medicated agenthaving a dispensing means also opening into said breathing means, andmeans connected to said breathing means and operative with saidtwo-position element for cyclically activating said dispensing meansupon inhalation and for deactivating said dispensing means uponexhalation of the patient, and mete-ring means in said dispensing meansfor controlling the amount of medication released into said breathingmeans.

3. A closed loop system for incrementally administering a predeterminedamount of medications to a patient comprising; a patients breathingmeans having a first opening adapted to be received by the patient, anoppositely positioned second opening including a two-position elementcyclically closing said opening upon inhalation and providing an airoutlet upon exhalation, an air vent means in said breathing means in anormally closed position, aerosolized medication dispensing means alsoopening into said breathing means, and means connected to said breathingmeans and operative with said two-position element for cyclicallyactivating said dispensing means and opening said air vent uponinhalation and for deactivating said anethetic dispensing means andclosing said air vent upon exhalation of said patient.

4. A closed loop system for incrementally administering a predeterminedamount of medications to a patient comprising; a patients breathingmeans having a first opening adapted to be received by the patient, anoppositely positioned second opening including a two-position elementcyclically closing said opening upon inhalation and providing an airoutlet upon exhalation of said patient,

an air vent means in said breathing means in a normally closed position,means containing an aerosolized medicated agent having dispensing meansalso opening into said breathing means, means connected to saidbreathing means and operative with said two-position element forcyclically activating said dispensing means and opening said air ventupon inhalation and for deactivating said dispensing means and closingsaid air vent upon exhalation of said patient, and metering means insaid dispensing means for controlling the amount of medication releasedinto said breathing means.

5. A closed loop system for incrementally administering a predeterminedamount of medications to a patient comprising; a patients breathingmeans having a first opening adapted to be received by the patient, anoppositely positioned second opening including a two-position elementclosing said opening upon inhalation and providing an air outlet uponexhalation, aerosolized medication dispensing means also opening intosaid breathing means; linkage means connected at one end to saiddispensing means, an electrical solenoid connected at the other end ofsaid linkage means, and a pressure activated electrical switchresponsive to pressure in said breathing means and operative with saidtwo-position element for energizing said solenoid and thereby movingsaid linkage means to activate said dispensing means upon inhalation andfor deactivating said dispensing mean-s upon exhalation of the patient.

6. A closed loop system for incrementally administering a predeterminedamount of medications to a patient comprising; a patients breathingmeans having a first opening adapted to be received by the patient, anoppositely positioned second opening including a two-position elementclosing said opening upon inhalation and providing an air outlet uponexhalation, aerosolized medication dispensing means also opening intosaid breathing means; linkage means connected at one end to saiddispensing means, an electrical solenoid connected at the other end ofsaid linkage means, and a pressure actuated electrical switch having anair tube entering said breathing means and operative with saidtwo-position element for energizing said solenoid and thereby movingsaid linkage means to activate said dispensing means upon inhalation andfor deactivating said dispensing means upon exhalation of the patient.

7. A closed loop system for incrementally administer ing a predeterminedamount of medications to a patient comprising; a patients breathingmeans having a first opening adapted to be received by the patient, anoppositely positioned second opening including a two-position elementclosing said opening upon inhalation and providing an air outlet uponexhalation of said patient, an air vent means in said breathing means ina normally closed position, means containing an aerosolized medicatedagent having dispensing means also opening into said breathing means;linkage means connected at one end to said dispensing means, anelectrical solenoid connected at the other end of said linkage means,said linkage being further connected to said air vent means, a pressureactuated electrical switch having an air tube entering said breathingmeans, and operative with said two-position element for energizing saidsolenoid and thereby moving said linkage means for activating saiddispensing means and opening said air vent upon inhalation and fordeactivating said dispensing means and closing said air vent uponexhalation of said patient.

8. A closed loop system for incrementally administering a predeterminedamount of medications to a patient comprising; a patient's breathingmeans having a first opening adapted to be received by the patient, anoppositely positioned second opening including a two-position elementclosing said opening upon inhalation and providing an air outlet uponexhalation of said patient, an air vent means in said breathing means ina normally closed position, means containing an aerosolized medicatedagent having dispensing means also opening into said breathing means;linkage means connected at one end of said dispensing means, anelectrical solenoid connected at the other end of said linkage means, apressure actuated electrical switch having an air tube entering saidbreathing means, and operative with said two-position element forenergizing said solenoid and thereby moving said linkage means foractivating said dispensing means and opening said air vent uponinhalation and for deactivating said dispensing means and closing saidair vent upon exhalation of said patient; a counter operative to advanceone position upon each closure of said switch, and stop means forterminating the operation of said system when said counter has advancedto a predetermined number.

9. A system as set forth in claim 8 wherein said medication is theanesthetic Xylocaine.

10. A system as set forth in claim 8 wherein said medication is theXylocaine dispersed in liquid Freon.

11. A system as set forth in claim 8 wherein said medication is theanesthetic Xylocaine dispersed in Freon and wherein said container meansis maintained under pressure to retain said Freon in a liquid stateuntil released into said breathing means.

12. incrementally administering a predetermined amount of medication toa patient comprising aerosolizing said medication, meteringpredetermined amounts of said medication, dispensing one of said meteredamounts, guiding internally of said patients said dispensed medication,sensing said patients inhalation and exhalation cyclically controllingthe dispensing of said medication in response to the inhalation andexhalation of said patient, providing an outlet for said patientexhalation, cyclically repeating dispensing said metered amountsinternally of said patient, and terminating said administration ofmedication upon reaching a predetermined total amount.

13. Inc-rementally administering a predetermined amount of anesthetic toa patient comprising pressurizing Xylocaine in a carrying agent,metering predetermined amounts of said anesthetic, dispensing one ofsaid metered amounts, guiding internally of said patient said dispensedanesthetic, sens-ing said patients inhalation and exhalation cyclicallycontrolling the dispensing of said anesthetic in response to theinhalation and exhalation of said patient, providing an outlet for saidpatient exhalation, cyclically repeating dispensing said metered amountsinternally of said patient, and terminating said administration ofanesthetic upon reaching a predetermined total amount.

14. Incrementally administering a predetermined amount of anesthetic toa patient comprising aerosolizing an anesthetic, metering predeterminedamounts of said anesthetic, dispensing one of said metered amounts,guiding internally of said patient said dispensed anesthetic, sensingsaid patients inhalation and exhalation cyclically controlling thedispensing of said anesthetic in response to the inhalation andexhalation of said patient, providing an outlet for said patientexhalation, cyclically repeating dispensing said metered amountsinternally of said patient, and terminating said administration ofanesthetic upon reaching a predetermined total amount.

References Cited UNITED STATES PATENTS 2,754,819 7/1956 Kirschbaum128-188 3,083,707 4/1963 Seeler 128194 XR 3,126,001 3/1964 Engstrom128188 XR 3,138,289 6/1964 Jones et a1. 222-20 XR 3,151,618 10/1964Wakernan 128203 3,187,748 6/1965 Mitchell et al. 128-208 XR RICHARD A.GAUDET, Primary Examiner.

W. E. KAMM, Examiner.

1. A CLOSED LOOP SYSTEM FOR INCREMENTALLY ADMINISTERING A PREDETERMINEDAMOUNT OF MEDICATIONS TO A PATIENT COMPRISING; A PATIENT''S BREATHINGMEANS HAVING A FIRST OPENING ADAPTED TO BE RECEIVED BY THE PATIENT, ANOPPOSITELY POSITIONED SECOND OPENING INCLUDING A TWO-POSITION ELEMENTCYCLICALLY CLOSING SAID OPENING UPON INHALATION AND PROVIDING AN AIROUTLET UPON EXHALATION, MEANS CONTAINING AN AEROSOLIZED MEDICATED AGENTHAVING A DISPENSING MEANS ALSO OPENING INTO SAID BREATHING MEANS, ANDMEANS CONNECTED TO SAID BREATHING MEANS AND OPERATIVE WITH SAIDTWO-POSITION ELEMENT FOR CYCLICALLY ACTIVATING SAID DISPENSING MEANSUPON INHALATIO AND FOR DEACIVATING SAID DISPENSING MEANS UPON EXHALATIONOF THE PATIENT.